Predictors of left atrial appendage thrombus in atrial fibrillation patients undergoing cardioversion.

BACKGROUND: Atrial fibrillation and atrial flutter represent the most prevalent clinically significant cardiac arrhythmias. While the CHA2DS2-VASc score is commonly used to inform anticoagulation therapy decisions for patients with these conditions, its predictive power is limited. Therefore, we sought to improve risk prediction for left atrial appendage thrombus (LAAT), a known risk factor for stroke in these patients. METHODS: We developed and validated an explainable machine learning model using the eXtreme Gradient Boosting algorithm with 5 × 5 nested cross-validation. The primary outcome was to predict the probability of LAAT in patients with atrial fibrillation and atrial flutter who underwent transesophageal echocardiogram prior to cardioversion. Our algorithm used 37 demographic, comorbid, and transthoracic echocardiographic variables. RESULTS: A total of 795 patients were included in our analysis. LAAT was present in 11.3% of the patients. The average age of patients was 63.3 years and 34.7% were women. Patients with LAAT had significantly lower left ventricular ejection fraction (29.9% vs 43.5%; p < 0.001), lower E' lateral velocity (5.7 cm vs. 7.9 cm; p < 0.001) and higher E/A ratio (2.6 vs 1.8; p = 0.002). Our machine learning model achieved a high AUC of 0.79, with a high specificity of 0.82, and modest sensitivity of 0.57. Left ventricular ejection fraction was the most important variable in predicting LAAT. Patients were split into 10 buckets based on the percentile of their predicted probability of having thrombus. The lower the percentile (e.g., 10%), the lower the probability of having thrombus. Using a cutoff point of 0.16 which includes 10.0% of the patients, we can rule out thrombus with 100% confidence. CONCLUSION: Using machine learning, we refined the predictive power of predicting LAAT and explained the model. These results show promise in providing better guidance for anticoagulation therapy and cardioversion in AF and AFL patients.

Autologous tolerogenic dendritic cells for rheumatoid and inflammatory arthritis.

OBJECTIVES: To assess the safety of intra-articular (IA) autologous tolerogenic dendritic cells (tolDC) in patients with inflammatory arthritis and an inflamed knee; to assess the feasibility and acceptability of the approach and to assess potential effects on local and systemic disease activities. METHODS: An unblinded, randomised, controlled, dose escalation Phase I trial. TolDC were differentiated from CD14+ monocytes and loaded with autologous synovial fluid as a source of autoantigens. Cohorts of three participants received 1×106, 3×106 or 10×106 tolDC arthroscopically following saline irrigation of an inflamed (target) knee. Control participants received saline irrigation only. Primary outcome was flare of disease in the target knee within 5 days of treatment. Feasibility was assessed by successful tolDC manufacture and acceptability via patient questionnaire. Potential effects on disease activity were assessed by arthroscopic synovitis score, disease activity score (DAS)28 and Health Assessment Questionnaire (HAQ). Immunomodulatory effects were sought in peripheral blood. RESULTS: There were no target knee flares within 5 days of treatment. At day 14, arthroscopic synovitis was present in all participants except for one who received 10×106 tolDC; a further participant in this cohort declined day 14 arthroscopy because symptoms had remitted; both remained stable throughout 91 days of observation. There were no trends in DAS28 or HAQ score or consistent immunomodulatory effects in peripheral blood. 9 of 10 manufactured products met quality control release criteria; acceptability of the protocol by participants was high. CONCLUSION: IA tolDC therapy appears safe, feasible and acceptable. Knee symptoms stabilised in two patients who received 10×106 tolDC but no systemic clinical or immunomodulatory effects were detectable. TRIAL REGISTRATION NUMBER: NCT01352858.

A randomised controlled trial of etanercept and methotrexate to induce remission in early inflammatory arthritis: the EMPIRE trial.

OBJECTIVE: To compare the efficacy of etanercept (ETN) and methotrexate (MTX) versus MTX monotherapy for remission induction in patients with early inflammatory arthritis. METHODS: In a 78-week multicentre randomised placebo-controlled superiority trial, 110 DMARD-naïve patients with early clinical synovitis (≥1 tender and swollen joint, and within 3 months of diagnosis) and either rheumatoid factor, anticitrullinated protein antibodies or shared epitope positive were randomised 1:1 to receive MTX+ETN or MTX+placebo (PBO) for 52 weeks. Injections (ETN or PBO) were stopped in all patients at week 52. In those with no tender or swollen joints (NTSJ) for >26 weeks, injections were stopped early. If patients had NTSJ >12 weeks after stopping the injections, MTX was weaned. The primary endpoint was NTSJ at week 52. RESULTS: No statistically significant difference was seen for the primary endpoint (NTSJ at week 52 (32.5% vs 28.1% [adjusted OR 1.32 (0.56 to 3.09), p=0.522]) in the MTX+ETN and MTX+PBO groups, respectively). The secondary endpoints did not differ between groups at week 52 or 78. Exploratory analyses showed a higher proportions of patients with DAS28-CRP<2.6 in the MTX+ETN group at week 2 (38.5% vs 9.2%, adjusted OR 8.87 (2.53 to 31.17), p=0.001) and week 12 (65.1% vs 43.8%, adjusted OR 2.49 (1.12 to 5.54), p=0.026). CONCLUSIONS: In this group of patients with early inflammatory arthritis, almost a third had no tender, swollen joints after 1 year. MTX+ETN was not superior to MTX monotherapy in achieving this outcome. Clinical responses, however, including DAS28-CRP<2.6, were achieved earlier with MTX+ETN combination therapy. TRIAL REGISTRATION NUMBER: The EMPIRE trial is registered on the following trial registries: Eudract-2005-005467-29; ISRCTN 55428162 (http://www.controlled-trials.com/ISRCTN55428162/EMPIRE). The full trial protocol can be obtained from the corresponding author.

Remission induction comparing infliximab and high-dose intravenous steroid, followed by treat-to-target: a double-blind, randomised, controlled trial in new-onset, treatment-naive, rheumatoid arthritis (the IDEA study).

OBJECTIVES: In disease modifying antirheumatic drug (DMARD)-naive early rheumatoid arthritis (RA), to compare the efficacy of methotrexate (MTX) and infliximab (IFX) with MTX and intravenous corticosteroid for remission induction. METHODS: In a 78-week multicentre randomised controlled trial, double-blinded to week 26, 112 treatment-naive RA patients (1987 American College of Rheumatology classification criteria) with disease activity score 44 (DAS44)>2.4 were randomised to MTX + IFX or MTX + single dose intravenous methylprednisolone 250 mg. A treat-to-target approach was used with treatment escalation if DAS44>2.4. In the IFX group, IFX was discontinued for sustained remission (DAS44<1.6 for 6 months). The primary outcome was change in modified total Sharp-van der Heijde score (mTSS) at week 50. RESULTS: The mean changes in mTSS score at week 50 in the IFX and intravenous steroid groups were 1.20 units and 2.81 units, respectively (adjusted difference (95% CI) -1.45 (-3.35 to 0.45); p=0.132). Radiographic non-progression (mTSS<2.0) occurred in 81% vs 71% (OR 1.77 (0.56 to 5.61); p=0.328). DAS44 remission was achieved at week 50 in 49% and 36% (OR 2.13 (0.91 to 5.00); p=0.082), and at week 78 in 48% and 50% (OR 1.12 (0.47 to 2.68); p=0.792). Exploratory analyses suggested higher DAS28 remission at week 6 and less ultrasound synovitis at week 50 in the IFX group. Of the IFX group, 25% (14/55) achieved sustained remission and stopped IFX. No substantive differences in adverse events were seen. CONCLUSIONS: In DMARD-naive early RA patients, initial therapy with MTX+high-dose intravenous steroid resulted in good disease control with little structural damage. MTX+IFX was not statistically superior to MTX+intravenous steroid when combined with a treat-to-target approach.

Respiratory hamartoma in a cockatiel (Nymphicus hollandicus).

CASE REPORT: An 8-year-old female cockatiel (Nymphicus hollandicus) was presented with coelomic distension. Palpation revealed an irregular intracoelomic mass. An exploratory coeliotomy was performed and the mass successfully removed. Histopathology determined the mass to be a respiratory hamartoma. CONCLUSION: The bird recovered uneventfully and 2 years later showed no evidence of recurrence.

Neuroangiostrongyliasis due to Angiostrongylus cantonensis in gang-gang cockatoos (Callocephalon fimbriatum).

CASE REPORT: Four gang-gang cockatoos from an aviary in Sydney displayed severe neurological signs. Three were necropsied and histopathology of the brains and spinal cords revealed migrating nematodes, which were identified as Angiostrongylus cantonensis. The migrating larval nematodes created tracts of malacia in the brain, but elicited little inflammatory cell infiltration. However, adult nematodes that had emerged onto the meningeal surface of the spinal cord evoked a marked non-suppurative reaction. Detailed histological examination of other tissues revealed larvae embedded in arterioles in the gastrointestinal serosa, lung and heart, which were associated with a significant granulomatous response. The latter lesions were consistent with our understanding of the pathogenesis of infection with this parasite, but have not been previously described, probably as a result of limited sampling. CONCLUSIONS: Angiostrongylus cantonensis is still present in the Sydney area and can cause significant disease in exposed animals, including birds. It also highlights potential human health problems.

Detection of Aphanomyces invadans and epizootic ulcerative syndrome in the Murray-Darling drainage.

Epizootic ulcerative syndrome was diagnosed, and the presence of Aphanomyces invadans confirmed, from an outbreak of clinical disease in wild-caught bony bream (Nematalosa erebi) from the Darling River near Bourke, in New South Wales, Australia, during 2008. This confirms a significant extension of the agent beyond its historical range.

Potential role of arthroscopy in the management of inflammatory arthritis.

Despite its advantages in diagnosis, treatment and research, the role of arthroscopy in the management of rheumatic diseases has diminished due to the development of other less invasive means of joint assessment including advances in imaging techniques, e.g. ultrasound and magnetic resonance imaging. However, arthroscopy still provides invaluable information. By direct and precise internal inspection of a joint, arthroscopy allows the collection of synovial membrane samples (biopsies) of excellent quality, notably from the most representative pathological areas. Arthroscopy may also play a therapeutic role in the management of inflammatory arthritis (IA) by providing pain relief (lavage). Here we describe the procedure of knee arthroscopy under local anaesthesia, as well as an in situ visual assessment of synovial inflammation and its correlation with degree of histological and immunological abnormalities. With the emphasis being placed on early diagnosis and treatment initiation in patients with IA and as earlier initiation of targeted biologic therapies becomes more commonplace, the ability to predict which patients will respond to the different therapies available would be invaluable. Assessment of arthroscopic derived synovial biopsies has potential to play an important role in management of early IA in the future.

Pathological changes in horses dying with equine influenza in Australia, 2007.

Analysis of pathology results from the 2007 equine influenza (EI) outbreak in Australia indicate that young foals in naïve horse populations are prone to developing broncho-interstitial pneumonia, and that this can be a rare manifestation of EI virus infection in mature horses. All horses may develop secondary bacterial bronchopneumonia, with mature horses more likely to die. EI outbreaks among heavily pregnant mares can result in increased neonatal losses because of premature placental separation and dystocia causing fetal hypoxia.

Mesenchymal stem cells in rheumatoid synovium: enumeration and functional assessment in relation to synovial inflammation level.

OBJECTIVE: Achieving joint regeneration in rheumatoid arthritis (RA) represents a future challenge. Autologous synovial mesenchymal stem cells (MSCs) could be therapeutically exploited. However, the inflammatory milieu in the RA synovium could adversely affect endogenous MSC function. To test this hypothesis, the frequency and multipotency of RA synovial MSCs was evaluated in relation to existing synovial inflammation. METHODS: Synovial inflammation was measured using the arthroscopic visual analogue score (VAS) and further validated using immunohistochemistry and flow cytometry. Highly proliferative clonogenic in vivo MSCs were enumerated following fluorescence-activated cell sorting and expansion for 20 population doublings. MSC multipotency was quantified following standard in vitro culture expansion and trilineage differentiation assays. Real-time PCR, flow cytometry and ELISA were used to evaluate pro- and anti-chondrogenic molecules in standard polyclonal synovial MSCs. RESULTS: The arthroscopic VAS significantly correlated with synovial macrophage infiltration. In RA, synovial MSC chondrogenesis was inhibited in direct relation to VAS (r = -0.777, p<0.05) and reduced compared with control osteoarthritis (OA)-MSCs (p<0.05). In vivo, MSCs resided in the synovial fibroblastic/stromal fraction (CD45(-)CD31(-)) and were reduced in frequency in relation to VAS (r = -0.695, p<0.05). In RA-MSCs, CD44 levels correlated negatively with inflammation and positively with chondrogenesis (r = -0.830 and r = 0.865, respectively). Cytokine production and Sox9 expression was similar in RA-MSCs and OA-MSCs. CONCLUSIONS: There is a negative relationship between synovial MSC chondrogenic and clonogenic capacities and the magnitude of synovitis in RA. Effective suppression of joint inflammation is therefore necessary for the development of autologous MSC treatments aimed at cartilage regeneration in RA.

Mode of action of abatacept in rheumatoid arthritis patients having failed tumour necrosis factor blockade: a histological, gene expression and dynamic magnetic resonance imaging pilot study.

OBJECTIVES: Abatacept is the only agent currently approved to treat rheumatoid arthritis (RA) that targets the co-stimulatory signal required for full T-cell activation. No studies have been conducted on its effect on the synovium, the primary site of pathology. The aim of this study was to determine the synovial effect of abatacept in patients with RA and an inadequate response to tumour necrosis factor alpha (TNFalpha) blocking therapy. METHODS: This first mechanistic study incorporated both dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) and arthroscopy-acquired synovial biopsies before and 16 weeks after therapy, providing tissue for immunohistochemistry and quantitative real-time PCR analyses. RESULTS: Sixteen patients (13 women) were studied; all had previously failed TNFalpha-blocking therapy. Fifteen patients completed the study. Synovial biopsies showed a small reduction in cellular content, which was significant only for B cells. The quantitative PCR showed a reduction in expression for most inflammatory genes (Wald statistic of p<0.01 indicating a significant treatment effect), with particular reduction in IFNgamma of -52% (95% CI -73 to -15, p<0.05); this correlated well with MRI improvements. In addition, favourable changes in the osteoprotegerin and receptor activator of nuclear factor kappa B levels were noted. DCE-MRI showed a reduction of 15-40% in MRI parameters. CONCLUSION: These results indicate that abatacept reduces the inflammatory status of the synovium without disrupting cellular homeostasis. The reductions in gene expression influence bone positively and suggest a basis for the recently demonstrated radiological improvements that have been seen with abatacept treatment in patients with RA.

Cerebellar ataxia in sheep grazing pastures infested with Romulea rosea (onion grass or Guildford grass).

There have been anecdotal reports since 1962 of 'staggers' in sheep grazing Romulea rosea infested pastures, but this is the first detailed account. In September 2005, a locomotor disorder developed in 12 of 120 Merino wethers that had grazed R. rosea infested pasture at Albury, New South Wales, over several months. Affected sheep displayed signs that included limb paresis, knuckling over in the fetlocks, fine head tremor, incoordination, and an equilibrium disturbance characterised by frequent falling. The microscopic examination of brain and spinal cord tissues from two affected sheep revealed mild vacuolation, occasional lymphocytic cuffing around blood vessels, mild Wallerian degeneration, and occasional glial cells that contained honey-brown cytoplasmic pigments. The most significant changes were found in the cerebellum, where there were decreased numbers of Purkinje cells, increased numbers of glial cells, scattered vacuoles and occasional swollen axons. Previous reports of cerebellar toxicoses in ruminants have involved goats and cattle and have been associated with the ingestion of six Solanum spp. The Purkinje cell loss in this type of disorder is ultimately extensive and consequently affected animals may survive, but will remain permanently disabled.

The value of synovial cytokine expression in predicting the clinical response to TNF antagonist therapy (infliximab).

OBJECTIVES: Clinical response to TNF-alpha blockade in the treatment of RA is heterogeneous. The study aims were to determine whether pre-treatment synovial cytokine expression predicted infliximab response and whether synovial changes after therapy correlated with response. METHODS: Fifty-one patients had arthroscopic biopsies of the knee joint prior to infliximab (3 mg/kg) treatment. Synovial tissue cell numbers (CD68 and CD3 positive) and cytokine expression (TNF-alpha, lymphotoxin-alpha, IL-1alpha, -beta and receptor antagonist, and IL-6) pre-treatment was assessed using semi-quantitative immunohistochemistry. Changes in these parameters were assessed 16 weeks after infliximab in 32 patients who underwent repeat arthroscopic biopsy. RESULTS: Of the total patients, 47% (n = 24) achieved an ACR20 response; 53% (n = 27) did not. Baseline synovial TNF-alpha, IL-1alpha and -beta expression did not differ between the two groups. No differences in baseline TNF-alpha levels were observed with ACR levels of response (ACR20 and ACR50/70 groups). Post-treatment biopsies (17 ACR responders, 15 ACR non-responders) revealed significant reductions in sub-lining layer TNF-alpha expression in both response and non-response groups with significant reduction in vascularity and membrane proliferation scores. The worst ACR non-responders (<20% CRP suppression) demonstrated no reduction in any of the parameters. CONCLUSION: Pre-treatment synovial TNF-alpha or IL-1 expression does not predict TNF blockade response. Both ACR response and non-response was associated with reduction in synovial TNF-alpha-level expression. Suppression in TNF-alpha levels was not observed in the worst non-responders. The improvements (including in vascularity), independent of ACR clinical response, are compatible with the reduced structural damage documented in all groups of patients independent of response.

Comparative histopathology of two serotypes of infectious bronchitis virus (T and n1/88) in laying hens and cockerels.

The comparative and sequential histopathology of different tissues of unvaccinated laying hens and cockerels were studied in chickens exposed to T and N1/88 strain of infectious bronchitis virus (IBV). The Harderian gland and trachea of hens and cockerels in both T- and N1/88-infected groups were damaged to a similar extent. The cecum was unaffected for both strains of IBV in both hens and cockerels. The sequential histopathological changes in hens revealed that IBV multiplies initially in the Harderian gland, then in the tracheal mucosa and simultaneously in the kidney and regions of the oviduct such as the magnum, tubular shell gland, and shell gland pouch. In cockerels, IBV multiplies first in the Harderian gland, then simultaneously in the trachea and kidney. Overall, the severity and persistence of lesions were greater in the kidneys of T-infected hens as compared with N1/88-infected hens. However, pathological changes in the kidney were mild in T- and N1/88-infected cockerels.

Histopathology of two serotypes of infectious bronchitis virus in laying hens vaccinated in the rearing phase.

The comparative histopathology of 2 different strains of infectious bronchitis virus (T and N1/ 88) in vaccinated hens was studied at 110 wk of age. The Harderian gland showed similar histopathology in T- and N1/88-infected hens. The trachea and kidney of challenged vaccinated hens were protected to a moderate extent, but the oviduct was protected to only a small extent. The severity and persistence of lesions were greater in tubular shell gland, shell gland pouch, and kidney of the T-infected hens, whereas, for the magnum, N1/88 had a greater effect.

Phosphorylation of Zn(II)2Cys6 proteins: a cause or effect of transcriptional activation?

Many Zn(II)2Cys6 transcriptional regulators exhibit changes in phosphorylation that are coincident with their roles in transcriptional activation. It is, however, unclear whether these changes occur as a cause of, or as a result of, transcriptional activation. In this paper, we explore the relationship between these two events and collate data available on the phosphorylation state of those transcriptional regulators where the relationship has not been clearly identified.

Leflunomide in rheumatoid arthritis: recommendations through a process of consensus.

OBJECTIVES: To determine, by consensus, the optimal use of leflunomide in rheumatoid arthritis (RA), using a multidisciplinary panel of experts and performing meta-analyses of available data. METHODS: A multidisciplinary panel of experts in RA was convened. Important questions, pertinent to the use of leflunomide in the treatment of RA, were defined by consensus at an initial meeting. Each question was allocated to subgroups of two or three members, who worked separately to prepare a balanced opinion, based on published literature, data from individual patients taking part in phase II and phase III clinical trials provided by Aventis, and data from a USA-based medical claims database (AETNA). The full group then reconvened to agree on an overall consensus statement. Recommendations concerning efficacy and tolerability versus comparator drugs and placebo were derived from two new meta-analyses. RESULTS: Leflunomide was at least as effective as sulphasalazine and methotrexate, and equally well tolerated on meta-analysis of trial data. Overall withdrawal rates for all adverse events were similar for all three drugs. Avoidance of the loading dose reduces 'nuisance' side-effects (e.g. nausea), but probably delays the onset of action. Adverse events could usually be managed by dose reduction and/or symptomatic therapy. CONCLUSIONS: On the basis of efficacy, safety and cost, leflunomide should be considered in patients with RA who have failed first-line DMARD drug therapy. In refractory cases, leflunomide may be used in combination with, for example, methotrexate before biological agents. Therapy should be initiated by a specialist, but repeat prescribing in general practice on a shared care basis is acceptable using agreed protocols. Clear mechanisms are required to monitor toxicity, with good communication between the patient and rheumatologist to manage nuisance side-effects and avoid unnecessary discontinuation of leflunomide.

Galactokinase: structure, function and role in type II galactosemia.

The conversion of beta- D-galactose to glucose 1-phosphate is accomplished by the action of four enzymes that constitute the Leloir pathway. Galactokinase catalyzes the second step in this pathway, namely the conversion of alpha- D-galactose to galactose 1-phosphate. The enzyme has attracted significant research attention because of its important metabolic role, the fact that defects in the human enzyme can result in the diseased state referred to as galactosemia, and most recently for its utilization via 'directed evolution' to create new natural and unnatural sugar 1-phosphates. Additionally, galactokinase-like molecules have been shown to act as sensors for the intracellular concentration of galactose and, under suitable conditions, to function as transcriptional regulators. This review focuses on the recent X-ray crystallographic analyses of galactokinase and places the molecular architecture of this protein in context with the extensive biochemical data that have accumulated over the last 40 years regarding this fascinating small molecule kinase.